Abstract: This Article analyzes the long-term impact on firm behavior of the repatriation tax holiday of the American Jobs Creation Act of 2004 (AJCA). The approach taken is empirical and based on data collected from the public filings of large U.S.-based multinational corporations. Statistical analysis of the data shows that there has been a dramatic increase in the rate at which firms add to their stockpile of foreign earnings kept overseas. Further analysis shows that this change has been driven both by an increase in the fraction of foreign earnings that remain permanently invested abroad and, in the case of some categories of firms, by an increase in foreign earnings relative to domestic earnings. These findings are consistent with the hypothesis that the temporary holiday conditioned firms to anticipate future such holidays and to change their behavior by placing more earnings overseas than ever before. Thus, although the AJCA was a short-term success in getting foreign earnings repatriated, it may have been a long-term failure by creating a long-term net increase in total earnings kept overseas. The findings of this Article are useful not only for evaluating the AJCA specifically but also for demonstrating more generally the speed and degree to which behavioral effects based on conditioning can occur in the wake of a holiday or other amnesty, particularly in situations involving substantial economic stakes.